Research And Application Of Process Planning For Typical Automotive Parts Based On PLM Platform

Process planning is an important segment of parts manufacturing,which has a direct and significant impact on product quality,production time and cost.Therefore,process planning has always been a research hotspot in the field of manufacturing.Moreover,automotive parts manufacturing industry is a typical discrete manufacturing industry,with particular emphasis on the process planning of components.This thesis relies on the national key project undertaken by an enterprise and university.In this thesis,the problems of long process design cycle,high work intensity of process designers and low degree of automation in the process of traditional machining process planning are studied.Combining with the research results of computer intelligent technology,the storage method and content of process knowledge in process database,the similarity calculation of feature attributes in case retrieval,and the process sequencing are discussed,and the PLM platform is used for secondary development to realize the computer-aided process planning of typical automotive parts.The main content of this thesis has the following aspects:1.The surface features and processing technology knowledge of typical automotive parts are analyzed,the content and storage method of process knowledge is determined,and the standardized process database is establish based on SQL Server database,so as to facilitate the transmission and sharing of knowledge.2.Based on the process database,the CBR method is used in process planning for the target parts to be processed of the reusable process example.The method of hierarchical retrieval method is used to calculate the similarity of the basic attribute information and the process characteristic attribute information of the part.A composite similarity calculation method based on Euclidean distance,cosine similarity and grey relational analysis method is developed to calculate the similarity of process feature attribute information of parts,which effectively improves the matching accuracy of the example.3.Based on knowledge reasoning,the ant colony algorithm with elite strategy is used to sort the parts processing route for the target parts that lack the reusable process examples.Constrained by the precision and roughness of the feature,based on the feature knowledge of the process knowledge base,the processing method is matched to the processing method of the target part,and the processing primitive is generated;and the priority constraint matrix of the processing primitive is constructed according to the process constraint rule;Combining the ant colony algorithm with elite strategy,with the least number of process equipment transformations and the shortest route,the optimal processing primitive ordering scheme is generated,and the decision of the part processing process plan is made according to the scheme.4.The process planning module is developed based on the original PLM platform,and a typical part of the main reducer is taken as an analysis case to illustrate the design of the process retrieval module and process planning module.